formalize.checks module API documention

formalize.checks.assert_true(predicate, message)

Raise a ValidationError if predicate is not True

formalize.checks.assert_false(predicate, message)

Raise a ValidationError if predicate is not False

formalize.checks.test(func, message)

Allow an arbitrary test via a function (or lambda) returning a boolean value.

Example:

>>> from formalize import FormValidator, Unicode, Using
>>> banned = ['password', 'letmein', '123456']
>>> v = FormValidator()(
...     password=Unicode()(
...         test(lambda value: value not in banned, u"Password is too simple")
...     )
... )
>>> v.process({'password': 'hello'})
{'password': u'hello'}
>>> v.process({'password': 'password'}) 
Traceback (most recent call last):
 ...
ValidationError: ValidationError([('password', u'Password is too simple')])

This can also be combined with Using:

>>> from formalize import FormValidator, Unicode, Using
>>> v = FormValidator()(
...     oldpassword=Unicode(),
...     newpassword=Unicode()(
...         Using('newpassword', 'oldpassword')(test(lambda new, old: old != new, u"New password cannot be the same as your old password"))
...     )
... )
>>> v.process({'oldpassword': 'sliced', 'newpassword': 'bread'}) == {'oldpassword': 'sliced', 'newpassword': 'bread'}
True
>>> v.process({'oldpassword': 'sliced', 'newpassword': 'sliced'})
Traceback (most recent call last):
 ...
ValidationError: ValidationError([('newpassword', u'New password cannot be the same as your old password')])

formalize.checks.maxlen(l, message=None)

Synopsis:

>>> from formalize import FormValidator, Unicode
>>> v = FormValidator()(

... username=Unicode()(maxlen(20, message=u’Username is too long’)) ... ) >>> v.process({‘username’: ‘abcdefghijklmnopqrstu’}) # doctest: +ELLIPSIS Traceback (most recent call last):

...

ValidationError: ValidationError([(‘username’, u’Username is too long’)])

formalize.checks.minlen(l, message=None)

Synopsis:

>>> from formalize import FormValidator, Unicode
>>> v = FormValidator()(

... password=Unicode()(minlen(6, message=u”Password is too short”)) ... ) >>> v.process({‘password’: ‘hello’}) # doctest: +ELLIPSIS Traceback (most recent call last):

...

ValidationError: ValidationError([(‘password’, u’Password is too short’)])

formalize.checks.greaterthan(l, message=None)

Synopsis:

>>> from formalize import FormValidator, Int
>>> v = FormValidator()(

... age=Int()(greaterthan(18, message=u’You must be at least 18 years old’)) ... ) >>> v.process({‘age’: ‘8’}) # doctest: +ELLIPSIS Traceback (most recent call last):

...

ValidationError: ValidationError([(‘age’, u’You must be at least 18 years old’)])

formalize.checks.lessthan(l, message=None)

Synopsis:

>>> from formalize import FormValidator, Int
>>> v = FormValidator()(

... day=Int()(lessthan(7, message=u’Value must be less than 7’)) ... ) >>> v.process({‘day’: ‘8’}) # doctest: +ELLIPSIS Traceback (most recent call last):

...

ValidationError: ValidationError([(‘day’, u’Value must be less than 7’)])

formalize.checks.matches(p, message=None)

Synopsis:

>>> from formalize import FormValidator, Unicode
>>> v = FormValidator()(

... code=Unicode()(matches(r’^[a-z0-9]+$’, u’Please only lower case letters and digits’)) ... ) >>> v.process({‘code’: ‘A1’}) # doctest: +ELLIPSIS Traceback (most recent call last):

...

ValidationError: ValidationError([(‘code’, u’Please only lower case letters and digits’)])

formalize.checks.looks_like_email(message=None)

Check that the value is superficially like an email address, ie that it contains a local part and domain, separated with an @.

Beyond this it is rather difficult to verify an email address (and technically valid RFC2822 email addresses may still break your application code - the range of what counts as valid is notoriously wide).

Synopsis:

>>> from formalize import FormValidator, Unicode
>>> v = FormValidator()(
...     email=Unicode()(looks_like_email(message=u'Please supply an email address'))
... )
>>> v.process({'email': 'me at example dot com'}) 
Traceback (most recent call last):
 ...
ValidationError: ValidationError([('email', u'Please supply an email address')])

formalize.checks.maxwords(count, message=None)

Check that the value has no more than count words

Synopsis:

>>> from formalize import FormValidator, Unicode
>>> v = FormValidator()(
...     message=Unicode()(maxwords(2, message=u"Value is too long"))
... )
>>> v.process({'message': u'hello world!'})
{'message': u'hello world!'}

>>> v.process({'message': u'to be or not to be'})
Traceback (most recent call last):
 ...
ValidationError: ValidationError([('message', u'Value is too long')])

formalize.checks.minwords(count, message=None)

Check that the value has at least count words

Synopsis:

>>> from formalize import FormValidator, Unicode
>>> v = FormValidator()(
...     message=Unicode()(minwords(3, message=u"Value is too short"))
... )
>>> v.process({'message': u'to be or not to be'})
{'message': u'to be or not to be'}
>>> v.process({'message': u'hello world'}) 
Traceback (most recent call last):
 ...
ValidationError: ValidationError([('message', u'Value is too short')])

formalize.checks.equals(testvalue, message=None)

Synopsis:

>>> from formalize import FormValidator, Bool
>>> v = FormValidator()(

... terms_accepted=Bool()(equals(True, u’Please accept the terms of service to continue’)) ... ) >>> v.process({‘terms_accepted’: ‘’}) # doctest: +ELLIPSIS Traceback (most recent call last):

...

ValidationError: ValidationError([(‘terms_accepted’, u’Please accept the terms of service to continue’)])

formalize.checks.notempty(message=None)

Check that a string value is not empty or whitespace

Synopsis:

>>> from formalize import FormValidator, Unicode
>>> v = FormValidator()(
...     name=Unicode()(notempty(message=u'Value is required'))
... )
>>> v.process({'name': ''}) 
Traceback (most recent call last):
 ...
ValidationError: ValidationError([('name', u'Value is required')])

formalize.checks.is_in(values, message=None)

Synopsis:

>>> from formalize import FormValidator, Unicode
>>> v = FormValidator()(

... terms_accepted=Unicode()(is_in([‘Y’, ‘N’], u’Please answer yes or no’)) ... ) >>> v.process({‘terms_accepted’: ‘maybe’}) # doctest: +ELLIPSIS Traceback (most recent call last):

...

ValidationError: ValidationError([(‘terms_accepted’, u’Please answer yes or no’)])